heat exchanger

Abstract

A cartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, the cartridge heat exchanger comprising a cartridge body having first working fluid inlet and outlet ports disposed at opposite ends and second working fluid inlet and outlet ports disposed at opposite sides, wherein an interior wall structure of the cartridge body defines a plurality of first working fluid conduits ("first conduits") extending between the first working fluid inlet and outlet ports from one end to the other of the cartridge body, the first conduits having an elongated cross-sectional dimension, the first conduits being spaced apart from one another, and the spaces between adjacent first conduit walls define second working fluid conduits ("second conduits") extending from one side of the cartridge body to the other side between the second working fluid inlet and outlet ports. The sealing surface is disposed around the cartridge body and separates the first working fluid inlet and outlet ports from the second working fluid inlet and outlet ports, the cartridge body is sealable within the housing, the first working fluid inlet and outlet ducts are in fluid communication with the first working fluid inlet and outlet ports, and the second working fluid inlet and outlet ducts are in fluid communication with the second working fluid inlet and outlet ports.

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger.

[0002] In particular, the present disclosure relates to heat exchangers configured to be contained within a housing. The term "cartridge heat exchanger" is used throughout this specification to refer to this type of heat exchanger, which has a core structure configured to fit inside and be sealed within a separate housing. The housing may be a freestanding structure or may be integral with other components, such as the housing of a gearbox.

[0003] More specifically, the present disclosure relates to microcartridge heat exchangers, in which a typical cartridge heat exchanger has fluid flowing through one or more conduits having lateral dimensions generally less than 1 mm. [Background technology]

[0004] Microcartridge heat exchangers are lightweight, highly compact, and efficient due to the heat exchange conduits' small lateral dimensions and resulting high surface area density for heat transfer. This compactness makes them suitable for a variety of applications, particularly in the aerospace and automotive / motorsport sectors.

[0005] Existing microcartridge heat exchangers are typically microtube cartridge heat exchangers, which have two parallel, spaced-apart tube plates connected by a plurality of straight microtubes. Each microtube typically has a diameter of less than 1 mm. During use, a first fluid flows through the microtubes and a second fluid flows outside the microtubes. The microtubes may include hypodermic tubes.

[0006] Conventional manufacturing methods for microtube cartridge heat exchangers involve laboriously placing and joining (e.g., brazing, soldering, or gluing) hundreds to thousands of microtubes to each tube plate. This expensive process requires the fabrication of many individual parts and subsequent laborious assembly of the parts, resulting in long manufacturing times. Additionally, conventional manual assembly methods can easily result in poor connections and seals between components, leading to high scrap rates and / or ultimate failure of the heat exchanger. Furthermore, conventional processes are largely inflexible, and design changes typically require the replacement of numerous fabricated parts and fixture components.

[0007] Conventional microtube cartridge heat exchangers are typically limited to straight tube geometries. FIG. 1 shows a side elevation view of a conventional microtube cartridge heat exchanger 1000 configured with a first fluid flow path through the microtubes 1006 in a direction 1012 and a second fluid flow path between the microtubes 1006 (i.e., into the page). To form a seal between the heat exchanger's tube plates 1002, 1004 and the external housing and maintain separation of the two fluid regions, the tube plates necessarily protrude outward from the microtube 1006 arrangement. To maintain uniform fluid flow between the microtubes, the spaces on each side of a conventional heat exchanger defined by the tube plate protrusions, the straight microtubes, and the housing wall must be shielded with a filler plate 1010. That is, the filler plate is necessary to shield these spaces and reduce the flow rate of fluid bypassing the active heat transfer area. It will be appreciated that the packing plates result in wasted space on the sides of the heat exchanger and reduced efficiency of heat transfer.

[0008] The limitation of conventional microtubular cartridge heat exchangers to straight tubes also limits the ability to vary the surface area ratio between the two fluid regions, which is effectively fixed by the inner and outer diameters of a hypodermic needle.

[0009] As such, there is a need for an improved microcartridge heat exchanger. Summary of the Invention

[0010] According to one aspect of the present invention, there is provided a microcartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, the microcartridge heat exchanger comprising: a first plate defining an inlet for the first working fluid; a second plate defining an outlet for the first working fluid; a plurality of conduits ("first working fluid conduits") disposed between the first and second plates and defining a first working fluid flow path through which, in use, the first working fluid flows; and a plurality of conduits ("second working fluid conduits") disposed between the first and second plates and defining a second working fluid flow path through which, in use, a second working fluid flows, the first and second working fluid conduits being arranged in alternating layers; The arrangement extends to substantially the outermost edges of each of the first and second plates, and the microcartridge heat exchanger is configured to be contained in a housing having a first working fluid inlet duct, a first working fluid outlet duct, a second working fluid inlet duct and a second working fluid outlet duct, and the configuration is such that when the microcartridge heat exchanger is within the housing, the first working fluid inlet duct is fluidly connected to an inlet for the first working fluid, the first working fluid outlet duct is fluidly connected to an outlet for the first working fluid, and the second working fluid inlet and outlet ducts are fluidly connected to a second working fluid conduit.

[0011] The first and second working fluid conduits may extend substantially perpendicular to the first and second plates.

[0012] The first and second plates may define upper and lower sides, respectively, of the heat exchanger, and the walls of the first working fluid conduit or the walls of the second working fluid conduit define first and second opposing lateral sides, respectively, of the heat exchanger, with the first working fluid conduit and / or the second working fluid conduit extending between third and fourth opposing lateral sides of the heat exchanger.

[0013] The size of the first plate may be different from the size of the second plate, such that the walls of the first working fluid conduit or the walls of the second working fluid conduit defining each of the first and second lateral sides of the heat exchanger are non-planar.

[0014] When the heat exchanger is housed in a housing, the second working fluid inlet duct may be adjacent to a third lateral side of the heat exchanger, and the second working fluid outlet duct may be adjacent to a fourth lateral side of the heat exchanger.

[0015] The first working fluid conduit may include a series of flat tubes, each extending vertically between the first and second plates and horizontally between the third and fourth sides of the heat exchanger.

[0016] The microcartridge heat exchanger may further include turbulators disposed within each of the flat tubes.

[0017] The second working fluid conduit may have a series of finned chambers, each extending vertically between the first and second plates and horizontally between the third and fourth lateral sides of the heat exchanger.

[0018] The first and second working fluid flow paths may be perpendicular to one another, defining a cross-flow configuration.

[0019] The microcartridge heat exchanger may have a unitary and seamless structure.

[0020] In yet another aspect of the present invention, there is provided a heat transfer assembly comprising the microcartridge heat exchanger described above and a housing having an opening into which the microcartridge heat exchanger is mounted, the housing further comprising a first working fluid inlet duct in fluid communication with the inlet for the first working fluid, a first working fluid outlet duct in fluid communication with the outlet for the first working fluid, a second working fluid inlet duct in fluid communication with the second working fluid conduit, and a second working fluid outlet duct in fluid communication with the second working fluid conduit.

[0021] The housing may have a first working fluid manifold interposed between the first working fluid inlet duct and the inlet for the first working fluid and in fluid communication with each of them, and a second working fluid manifold interposed between the second working fluid inlet duct and the second working fluid conduit and in communication with each of them.

[0022] Each of the first and second lateral sides of the heat exchanger may be directly adjacent a lateral wall of the opening in the housing.

[0023] In yet another aspect of the invention, there is provided a microcartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, the microcartridge heat exchanger comprising: a first plate defining an upper side of the heat exchanger and including an inlet for a first working fluid; a second plate defining a lower side of the heat exchanger and including an outlet for the first working fluid; a plurality of flat tubes, each extending vertically between the first and second plates, the plurality of flat tubes defining a first working fluid flow path through which the first working fluid flows in use; and a plurality of finned chambers, each extending vertically between the first and second plates and horizontally between a front side and a rear side of the heat exchanger, the plurality of finned chambers defining a second working fluid flow path through which the second working fluid flows in use, the flat tubes and finned chambers , arranged in alternating layers, the arrangement extending to substantially the outermost edges of the first and second plates, respectively, and first and second opposing lateral sides of such a heat exchanger being defined by flat tube walls or finned chamber walls, respectively; the microcartridge heat exchanger being configured to be contained in a housing, the housing comprising a first working fluid inlet duct, a first working fluid outlet duct, a second working fluid inlet duct and a second working fluid outlet duct, the configuration being such that when the microcartridge heat exchanger is within the housing, the first working fluid inlet duct is fluidly connected to the inlet for the first working fluid, the first working fluid outlet duct is fluidly connected to the outlet for the first working fluid, and the second working fluid inlet duct and outlet duct are fluidly connected to the finned chamber.

[0024] The microcartridge heat exchanger may further include turbulators disposed within each of the flat tubes.

[0025] The turbulators may have a plurality of pin-like structures, each extending across the width of the flat tube.

[0026] The finned chamber may have a plurality of chevron-shaped fins, each chevron-shaped fin being pierced by a plurality of openings.

[0027] In yet another aspect of the present invention, there is provided a heat transfer assembly comprising the microcartridge heat exchanger described above and a housing having an opening into which the microcartridge heat exchanger is mounted, the housing further comprising a first working fluid inlet duct in fluid communication with the inlet for the first working fluid, a first working fluid outlet duct in fluid communication with the outlet for the first working fluid, a second working fluid inlet duct in fluid communication with the finned chamber, and a second working fluid outlet duct in fluid communication with the finned chamber.

[0028] Each of the first and second lateral sides of the heat exchanger is directly adjacent a lateral wall of the opening in the housing.

[0029] In yet another aspect of the invention, there is provided a microcartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, the microcartridge heat exchanger comprising: a first plate defining an inlet for the first working fluid; a second plate defining an outlet for the first working fluid; a plurality of conduits ("first working fluid conduits") disposed between the first and second plates and defining a first working fluid flow path through which, in use, the first working fluid flows; and a plurality of conduits ("second working fluid conduits") disposed between the first and second plates and defining a second working fluid flow path through which, in use, a second working fluid flows; the first and second working fluid conduits being arranged in alternating layers. The plate and the working fluid conduit are integrally formed with each other, and the microcartridge heat exchanger is configured to be contained in a housing, the housing having a first working fluid inlet duct, a first working fluid outlet duct, a second working fluid inlet duct and a second working fluid outlet duct, such that when the microcartridge heat exchanger is in the housing, the first working fluid inlet duct is in fluid communication with an inlet for the first working fluid, the first working fluid outlet duct is in fluid communication with an outlet for the first working fluid, and the second working fluid inlet and outlet ducts are in fluid communication with the second working fluid conduit.

[0030] The present invention also provides a cartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, the cartridge body having first working fluid inlet and outlet ports located at opposite ends and second working fluid inlet and outlet ports located at opposite sides, an inner wall structure defining a plurality of first working fluid conduits ("first conduits") extending from one end of the cartridge body to the other between the first working fluid inlet and outlet ports, the first conduits having an elongated cross-sectional dimension, the first conduits being spaced apart from one another, the spaces between adjacent first conduit walls defining second working fluid conduits ("second conduits") extending from one side of the cartridge body to the other between the second working fluid inlet and outlet ports; and sealing surfaces disposed around the cartridge body and separating first working fluid inlet and outlet ports from second working fluid inlet and outlet ports, the cartridge heat exchanger being configured to be contained within a housing, the housing having a first working fluid inlet duct, a first working fluid outlet duct, a second working fluid inlet duct and a second working fluid outlet duct, the configuration being such that when the cartridge heat exchanger is within the housing, the cartridge body is sealed to the housing at the respective sealing surfaces, and the first working fluid inlet and outlet ducts are in fluid communication with the first working fluid inlet and outlet ports, and the second working fluid inlet and outlet ducts are in fluid communication with the second working fluid inlet and outlet ports.

[0031] The first conduit may comprise a flat tube, or the first conduit may comprise a curved tube. The first conduit may be provided with turbulators extending between their walls to promote turbulent flow of the first working fluid in use.

[0032] In some embodiments, the spacing between adjacent first conduit walls (i.e., the width of the second conduit) is substantially constant. The second conduit preferably has a finned chamber in which an array of fins extends between adjacent walls. The fin array may include rows of chevron-shaped fins with through-holes aligned in the flow direction of the second working fluid. Adjacent rows of fins may be offset from one another to promote turbulent flow of the second working fluid during use.

[0033] In some embodiments, the sealing surface comprises a flange around the first actuation fluid inlet and outlet ports that provides a seal with the housing during use.

[0034] The cartridge heat exchanger may be formed by an additive manufacturing process. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a schematic side elevation view of a conventional microtube heat exchanger. [Figure 2] FIG. 2 is a perspective view of a microcartridge heat exchanger according to one embodiment. [Figure 3] FIG. 3 is a cross-sectional side elevation view of the heat exchanger of FIG. [Figure 3A] FIG. 3A is a cross-sectional view taken along line AA in FIG. [Figure 3B] FIG. 3B is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 4 is a side elevational view of the heat exchanger of FIG. [Figure 4A] FIG. 4A is a cross-sectional view taken along line CC in FIG. [Figure 5] FIG. 5 is an exploded view of a heat transfer assembly having the heat exchanger of FIG. 2 and a housing configured to receive the heat exchanger. [Figure 5A] FIG. 5A is a cutaway view of the heat transfer assembly of FIG. 5, showing the heat exchanger in position within the housing. [Figure 6]FIG. 6 is a detailed cutaway view of the heat transfer assembly showing the location of the heat exchanger side walls when housed within the housing. [Figure 7] FIG. 7 is a cross-sectional view taken along line CC in FIG. 3, annotating detail C. [Figure 7A] FIG. 7A is an enlarged view of detail C of FIG. [Figure 8] FIG. 8 is a side elevational view of the heat exchanger of FIG. [Figure 8A] FIG. 8A is a cross-sectional view taken along line BB in FIG. [Figure 8B] FIG. 8B is an enlarged view of detail D in FIG. 8A. [Figure 9] FIG. 9 is a perspective view of the microcartridge heat exchanger of FIG. 2 with the top plate removed. [Figure 9A] FIG. 9A is an enlarged view of detail E of FIG. [Figure 10] FIG. 10 is a perspective view of a cylindrical microcartridge heat exchanger according to another embodiment of the present invention. [Figure 11] FIG. 11 is a side view of the cylindrical cartridge heat exchanger of FIG. [Figure 12] FIG. 12 is a cross-sectional view through LL of the cylindrical cartridge heat exchanger shown in FIG. [Figure 13] FIG. 13 is an enlarged view of section M shown in FIG. [Figure 14] FIG. 14 is a perspective view of another configuration of a cylindrical microcartridge heat exchanger in accordance with one embodiment of the present invention. [Figure 15] FIG. 15 is a side view of the cylindrical cartridge heat exchanger of FIG. [Figure 16A] FIG. 16A is a cross-sectional view through NN of the cylindrical cartridge heat exchanger shown in FIG. [Figure 16B] FIG. 16B is a simplified cross-sectional view through OO of the cylindrical cartridge heat exchanger shown in FIG. [Figure 17]FIG. 17 is a perspective view of a heat transfer assembly having a housing and a cylindrical microcartridge heat exchanger in accordance with one embodiment of the present invention. [Figure 18] FIG. 18 is a side view of the heat transfer assembly housing. [Figure 19] FIG. 19 is a cross-sectional view taken along line FF in FIG. [Figure 20] FIG. 20 shows a longitudinal section through the heat transfer assembly as through GG in FIG. [Figure 21] FIG. 21 is an enlarged view of section H shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0036] The invention may be better understood through the following detailed description of embodiments thereof, given by way of non-limiting example only and made with reference to the accompanying drawings, in which: FIG. 2 illustrates a microcartridge heat exchanger 100 according to one embodiment, comprising a first plate 2 defining a first working fluid inlet 3 and a second plate 4 defining a first working fluid outlet 5. A plurality of first working fluid conduits 6 are disposed between the first and second plates 2, 4. The first working fluid conduits 6 define a first working fluid flow path (schematically illustrated as F1 in FIG. 5A ) through which the first working fluid flows during use. A plurality of second working fluid conduits 12 are also disposed between the first and second plates 2, 4. The second working fluid conduits 12 define a second working fluid flow path (schematically illustrated as F2 in FIG. 5A ) through which the second working fluid flows during use. The first working fluid conduits 6 and the second working fluid conduits 12 extend substantially perpendicular to the first and second plates 2, 4.

[0037] For ease of reference, the following positional references are used throughout this specification, although it should be understood that the actual heat exchanger assembly / operational orientation may vary. The upper and lower sides 40 and 42 of the heat exchanger are defined by the first and second plates 2 and 4, respectively. The opposing first and second lateral sides 44 and 46 of the heat exchanger are defined by the walls of the first working fluid conduit 6 or the walls of the second working fluid conduit 12, respectively (described in further detail below). The second working fluid conduit 12 extends between opposing third and fourth lateral sides 48 and 50 of the heat exchanger. In a preferred embodiment, the first working fluid conduit 6 also extends between the opposing third and fourth lateral sides 48 and 50 to maximize heat transfer area.

[0038] As can be seen more clearly in FIGS. 4 and 4A , the first and second working fluid conduits 6, 12 are arranged in alternating layers that extend substantially to the outermost edges 8, 10 of the first and second plates 2, 4, respectively. Thus, the first and second lateral sides 44, 46 of the heat exchanger are defined by the walls of the first or second working fluid conduits, respectively (both of these outermost walls are hereinafter referred to as 80). In the illustrated embodiment, the first plate 2 is larger than the second plate 4, and therefore the walls 80 defining the outermost layers of the arrangement are not planar. As shown in cross section, each wall 80 has a straight portion 84 extending downward from substantially the outermost edge of the first plate 2 and a curved portion 86 directed inward toward substantially the outermost edge of the second plate 4. As used herein, the phrase "extending substantially to" is intended to include an arrangement extending to approximately the outermost edges 8,10, although some qualifications may be made, for example, due to mechanical tolerances. In one embodiment, the arrangement of the fluid conduits 6,12 extends to approximately 0.25 mm from the outermost edges 8,10 of the first and second plates 2,4. In other embodiments, for example, the first and second plates 2,4 may be the same size and the wall 80 may be planar.

[0039] In contrast to prior art microtube heat exchangers, no packing plates are required on the sides of the heat exchanger to reduce fluid bypassing the working heat exchange surface. Instead, the heat exchange surface extends outward on both sides of the heat exchanger, i.e., the outermost working fluid conduits extend substantially to the outermost edges 8, 10 of the first and second plates 2, 4. Thus, the wasted space occupied by packing plates (such as plate 1010 shown in FIG. 1 ) on the first and second lateral sides of a conventional microtube heat exchanger is advantageously utilized for heat transfer in the present invention. It will be appreciated that this increases the heat transfer area / volume (i.e., compactness) of the heat exchanger and potentially improves performance.

[0040] The alternating layers of first and second working fluid conduits 6, 12 are directly adjacent to each other and extend substantially parallel to each other for efficient heat transfer.

[0041] The microcartridge heat exchanger 100 is configured to be housed in a housing 20. FIG. 5 shows the heat exchanger 100 housed in the housing 20, collectively defining a heat transfer assembly 500. More specifically, the heat exchanger 100 is mounted within a housing opening 90 in the housing 20. The housing 20 has a first working fluid inlet duct 22, a first working fluid outlet duct 24, a second working fluid inlet duct 26, and a second working fluid outlet duct 28. As shown in FIG. 5A, when the microcartridge heat exchanger 100 is within the housing 20, the first working fluid inlet duct 22 is in fluid communication with the inlet 3 to direct the first working fluid into the heat exchanger 100, and the first working fluid outlet duct 24 is in fluid communication with the outlet 5 to direct the first working fluid to the exterior of the heat exchanger.

[0042] Second working fluid inlet and outlet ducts 26, 28 are in fluid communication with the second working fluid conduit 12. In the illustrated embodiment, the second working fluid inlet duct 26 is adjacent to the inlet side 30 (corresponding to the third lateral side 48) of the heat exchanger 100 and directs the second working fluid toward the interior of the heat exchanger. The second working fluid outlet duct 28 is adjacent to the opposite outlet side 32 (corresponding to the fourth lateral side 50) of the heat exchanger and directs the second working fluid toward the exterior of the heat exchanger.

[0043] The housing 20 defines a first working fluid manifold 120, which is interposed between the first working fluid inlet duct 22 and the inlet 3 for the first working fluid and is in fluid communication with each of them. The housing also defines a second working fluid manifold (not shown), which is interposed between the second working fluid inlet duct 26 and the inlet side 30 of the second working fluid conduit 12 and is in fluid communication with each of them. The first and second working fluid manifolds serve to evenly distribute and supply the first and second working fluids to the respective first and second working fluid flow paths.

[0044] The illustrated embodiment is a single-pass heat exchanger, in which the first and second fluids each flow through the heat exchanger in a single pass, thereby optimizing heat transfer between the two fluids. Further, as illustrated, the first and second working fluid flow paths are perpendicular to one another, defining a cross-flow configuration.

[0045] FIG. 6 shows in more detail the relationship between the wall 80 of the outermost fluid conduit and the wall of the receiving opening 90 of the housing 20. Each of the first and second plates 2, 4 has an elongated groove 102, 104 that accommodates a sealing member (not shown), which may be, for example, an O-ring. The sealing member ensures sealing of the microcartridge heat exchanger within the receiving opening 90 of the housing. In the illustrated embodiment, the outermost fluid conduit is a second working fluid conduit, whose outermost walls 80 each extend directly adjacent to and substantially parallel to a respective side wall 92 of the opening 90. In one embodiment, there is a small gap of approximately 0.25 mm between each wall 80 and the side wall 92. This does not affect the sealing of the heat exchanger 100 within the housing 20, i.e., the uniform flow of the second working fluid through the second working fluid conduit 12.

[0046] 7A and 9A, as shown, the first working fluid conduit 6 comprises a series of flat plates or tubes, each extending vertically between the first and second plates 2, 4 and horizontally between the third and fourth sides 48, 50 of the heat exchanger. Each flat plate / tube is hollow and defines a first working fluid flow path. Turbulators 60 may be disposed within each flat tube to disrupt the laminar flow of the first working fluid within the tube, promoting mixing and turbulence and thereby increasing heat transfer efficiency. In the illustrated example, the turbulators 60 are provided as pin-like structures, each positioned across the width of the first working fluid conduit 6. A stack of turbulators 60 may be disposed across the height and length of each flat tube, spaced apart to define the first working fluid flow path. It will be appreciated that various characteristics of the turbulators 60, such as the shape and width of each turbulator and the spacing between the turbulators, can be adapted and optimized based on the particular application of the heat exchanger, e.g., the particular fluid properties of the first working fluid.

[0047] The second working fluid conduit 12 has a series of finned chambers, each extending vertically between the first and second plates 2, 4 and horizontally between the third and fourth sides 48, 50 of the heat exchanger. Fin structures 70 disposed within the second working fluid conduit 12 increase the surface area of the heat exchange surface. It will be appreciated that by varying the geometry of the fin structures, the surface area ratio between the two fluid regions can be optimized to suit the specific fluid characteristics and / or boundary conditions of the heat exchanger. The fins 70 also promote mixing and turbulence of the second working fluid, thereby increasing heat transfer efficiency. Furthermore, the fins 70 function to reinforce and improve the structural integrity of the chambers.

[0048] As can be seen more clearly in FIGS. 7A and 9A , the fin arrangement, when viewed in cross section, may have chevron-shaped fins 70 pierced by openings 74. Stacks of fins 70 may be provided along the height and width of the second working fluid conduit 12. Within each stack, the fins 70 are spaced apart to provide flow paths for the second working fluid. The openings 74 impart surface turbulence to the fins 70, promoting mixing and turbulent flow of the second working fluid rather than allowing the fluid to flow therethrough. Therefore, such surface turbulence may be provided in addition to or instead of protrusions, slits, etc. in the fins. In the illustrated embodiment, the chevron shape of the fins 70 and the diamond shape of the openings 74 are particularly optimized for additive manufacturing of heat exchangers. Because the fin stacks are spaced apart, the chevron-shaped openings 72 provide additional surface turbulence. It should be understood that the geometry and arrangement of the fins may be tailored to the particular application of the heat exchanger 100, for example, the particular fluid properties of the second working fluid.

[0049] While up to this point, cartridge heat exchanger 100 has been shown to have a generally rectangular shape, Figures 10 and 11 instead show cartridge heat exchanger 200, which has a generally cylindrical shape. Cylindrical cartridge heat exchanger 200 is configured to be housed in a cylindrical cartridge housing 400, seen in Figures 17-21. While cartridge heat exchangers 100 and 200 are quite different in appearance, they are similar in many respects in structure and operation. Like rectangular cartridge heat exchanger 100, cylindrical cartridge heat exchanger 200 operates in a single-pass, cross-flow configuration during use.

[0050] The cylindrical cartridge heat exchanger 200 has a generally cylindrical cartridge body 202 extending between first and second ends 210, 220. Each of the first and second ends has a respective cylindrical flange 212, 222 with a sealing surface. The heat exchanger body has an internal structure of walls 205 that define first working fluid conduits ("first conduits") 230 extending from an inlet port 232 at the first end to an outlet port 234 at the second end. As best seen in the cross-sectional view of FIG. 12 , each of the first conduits 230 has the form of a narrow slot whose width extends from one side of the cartridge body to the other. The first conduits 230 are arranged in layers with narrow gaps between them that contain second working fluid conduits ("second conduits") 250. The second conduits 250 extend from an inlet port 252 on one side of the heat exchanger to an outlet port 254 on the other side. In the embodiment shown in Figures 10-13, the cartridge heat exchanger 200 has nine first conduits 230 and ten second conduits 250 (two peripheral second conduits 250 are between the outer wall of the heat exchanger body and the outermost first conduit 230).

[0051] Similar to heat exchanger 100, turbulators may be disposed within each of the first conduits to provide structure and, during use, disrupt the laminar flow of the first working fluid, promoting mixing and turbulence and thereby increasing heat transfer efficiency. For example, the turbulators may be provided as pin-like structures, each disposed across a narrow width of the first working fluid conduit 230. Stacks of turbulators may be spaced apart from one another across the width and length of each of the first conduits 230 to define a flow path for the first working fluid. It will be appreciated that various characteristics of the turbulators, such as the shape and width of each turbulator and the spacing between turbulators, may be adapted and optimized based on the particular application of the heat exchanger, for example, based on the particular fluid properties of the first working fluid.

[0052] The second working fluid conduit 250 has a series of finned chambers, each extending from one side of the heat exchanger to the other. Fin structures 270 ( FIG. 13 ) disposed within the second working fluid conduit 250 increase the surface area of the heat exchange surface. It will be appreciated that by varying the geometry of the fin structures, the surface area ratio between the two fluid regions can be optimized for the specific fluid characteristics and / or boundary conditions of the heat exchanger. The fins 270 also promote mixing and turbulence of the second working fluid, thereby increasing heat transfer efficiency. Furthermore, the fins 270 function to reinforce and improve the structural integrity of the chambers. The structure and arrangement of the fins 270 can be the same as the fins 70 described above in connection with the first embodiment.

[0053] 14-16 show another cylindrical microcartridge heat exchanger 300. The cylindrical cartridge heat exchanger 300 is configured to be housed within the same type of cylindrical cartridge housing 400 as the heat exchanger 200 (described below).

[0054] The cylindrical cartridge heat exchanger 300 has a generally cylindrical cartridge body 302 extending between first and second ends 310, 320. Each of the first and second ends has a respective cylindrical flange 312, 322 of reduced diameter. The heat exchanger body has an internal structure of a wall 305 that defines first working fluid conduits ("first conduits") 330 extending from an inlet port 332 at the first end to an outlet port 334 at the second end. As best seen in the cross-sectional views of Figures 16A and 16B, each of the first conduits 330 is in the form of a narrow slot that extends from one side of the cartridge body to the other.

[0055] The primary difference between heat exchanger 300 compared to heat exchanger 200 lies in the configuration of the first and second conduits, which results in improved flow paths, particularly for the second working fluid. While heat exchanger 200 has conduits that extend linearly from one side of the heat exchanger body to the other, heat exchanger 300 has conduits that follow the contours of a cylindrical shell. This is best seen in FIG. 16B, which shows a simple cross section through heat exchanger 300 at OO in FIG. 15. As shown, the outermost slots of first conduit 330 arc outward at regular intervals from the outer shell, and successive layers of inner conduits 330 follow suit. As shown in FIG. 16A, the walls defining the conduits are curved in all three dimensions from one end of heat exchanger 300 to the other.

[0056] As previously mentioned, the first conduits 330 are arranged in layers with narrow gaps between them, which contain second working fluid conduits ("second conduits") 350. The second conduits 350 extend from an inlet port 352 on one side of the heat exchanger to an outlet port 354 on the other side, in this case following a somewhat convoluted path. In the embodiment shown in FIGS. 14-16, the cartridge heat exchanger 300 has nine first conduits 330 (including the central tube) and ten second conduits 350 (two peripheral second conduits 350 are between the outer wall 302 of the heat exchanger body and the outermost first conduits 330).

[0057] Each cylindrical cartridge heat exchanger 200, 300 is designed to be housed in a housing 400 to form a heat transfer assembly 500 (FIG. 17). The housing 400 has a housing body 410 with mounting bosses 414 at each corner for mounting the assembly 500 during use. The housing body defines a cylindrical interior chamber for housing the cartridge heat exchanger 200, 300. The housing body 410 also defines a longitudinal channel 412 on each side of the cylindrical chamber. Removable end caps 420, 430 fit onto the ends of the housing body 410 and seal to the housing body and cartridge heat exchanger. The end caps 420, 430 provide respective inlet and outlet ducts 422, 432 for a first working fluid. The inlet flow direction of the first working fluid is indicated by arrow 425, and the outlet flow direction is indicated by arrow 435. Thus, the bulk flow of the first working fluid through the housing and through the cartridge heat exchangers 200, 300 is axial.

[0058] As shown in FIGS. 20 and 21 , the end cap 420 fits snugly within the cylindrical interior chamber of the housing body 410 and is held in place by a snap ring 428. When in place, the end cap 420 is sealed to the end flange 212 of the cartridge heat exchanger 200 by a first O-ring 424 and to the interior surface of the housing body 410 by a second O-ring 426. An end cap 430 is similarly secured and sealed at the other end of the housing and heat exchanger cartridge. These seals prevent the first and second working fluids from leaking from the system and from mixing. When the end cap is fitted, a plenum space exists between the interior of the end cap and the end of the cartridge heat exchanger, which functions as a manifold for dividing the first working fluid to the inlet port 232 and the first conduit 230.

[0059] A second working fluid inlet duct 440 is provided at one end of the housing body, and a corresponding second working fluid outlet duct 450 is provided at the other end. The inlet duct 440 is connected to a longitudinal passage 412 on one side of the cylindrical interior passage, and the outlet duct 450 is connected to the longitudinal passage on the other side. The inlet flow direction of the second working fluid is indicated by arrow 445, and the outlet flow is indicated by arrow 455. The longitudinal passage 412 allows the second working fluid to flow axially along the side of the heat exchanger from the inlet end to the outlet end, with the bulk flow of the second working fluid through the cartridge heat exchanger 200, 300 being transverse to the axis from one side to the other.

[0060] The micro cartridge heat exchangers disclosed herein are preferably of integrated, single, seamless construction, i.e., the entire micro heat exchanger is produced as a single piece, without the need for subsequent assembly of conduits to plates, thereby reducing manufacturing costs and eliminating the risk of leaks that affected prior art micro heat exchangers due to poor assembled (e.g., brazed) joints.

[0061] Additionally, producing microcartridge heat exchangers via additive manufacturing allows for greater control over the parameters of the heat exchange conduits and surfaces. More complex geometries can be provided, and the geometries can be more freely adapted and optimized based on the heat exchanger's application. For example, the geometries can be tailored to the heat exchanger's specific fluid properties, specific geometric constraints and requirements, and / or specific boundary conditions, which can improve performance compared to conventional heat exchangers with comparable volumes. Furthermore, changes to the geometry do not require the replacement of numerous manufacturing and assembly components.

[0062] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to those skilled in the art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Therefore, the present invention should not be limited by any of the illustrative embodiments described above.

[0063] The reference in this specification to any prior publication (or information derived therefrom) or public knowledge should not be taken as an admission or acknowledgement or suggestion that the prior publication (or information derived therefrom) or public knowledge forms part of the common general knowledge in the field of endeavor to which this specification pertains.

[0064] Throughout this specification and the claims that follow, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" will be understood to imply the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of other integers or steps or groups of integers or steps.

Claims

1. 1. A microcartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, comprising: a first plate defining an inlet for a first working fluid; a second plate defining an outlet for the first working fluid; a plurality of conduits ("first working fluid conduits") disposed across the first plate and the second plate and defining a first working fluid flow path through which a first working fluid flows in use; a plurality of conduits ("second working fluid conduits") disposed across the first plate and the second plate and defining second working fluid flow paths through which a second working fluid flows in use; and the first and second working fluid conduits are arranged in alternating layers, the arrangement extending to substantially the outermost edges of each of the first and second plates; the microcartridge heat exchanger is configured to be contained in a housing, the housing having a first working fluid inlet duct, a first working fluid outlet duct, a second working fluid inlet duct and a second working fluid outlet duct, the configuration being such that when the microcartridge heat exchanger is in the housing, the first working fluid inlet duct is in fluid communication with the inlet for the first working fluid, the first working fluid outlet duct is in fluid communication with the outlet for the first working fluid, and the second working fluid inlet and outlet ducts are in fluid communication with the second working fluid conduit; Microcartridge heat exchanger.

2. The microcartridge heat exchanger of claim 1 , wherein the first working fluid conduit and the second working fluid conduit extend substantially perpendicular to the first and second plates.

3. 3. A microcartridge heat exchanger as described in claim 1 or 2, wherein the first and second plates define upper and lower sides of the heat exchanger, respectively, and the walls of the first working fluid conduit or the walls of the second working fluid conduit define first and second opposing lateral sides of the heat exchanger, respectively, and the first working fluid conduit and / or the second working fluid conduit extend between the third and fourth opposing lateral sides of the heat exchanger.

4. 4. The microcartridge heat exchanger of claim 3, wherein the size of the first plate is different from the size of the second plate, such that the walls of the first working fluid conduit or the walls of the second working fluid conduit defining each of the first and second lateral sides of the heat exchanger are non-planar.

5. 5. A microcartridge heat exchanger as described in claim 3 or 4, wherein when the heat exchanger is contained in a housing, the second working fluid inlet duct is adjacent to a third lateral side of the heat exchanger and the second working fluid outlet duct is adjacent to a fourth lateral side of the heat exchanger.

6. 6. A microcartridge heat exchanger as described in any one of claims 3 to 5, wherein the first working fluid conduit comprises a series of flat tubes, each extending vertically between the first and second plates and horizontally between the third and fourth sides of the heat exchanger.

7. 7. The microcartridge heat exchanger of claim 6, further comprising turbulators disposed within each flat tube.

8. 8. A microcartridge heat exchanger as described in any one of claims 3 to 7, wherein the second working fluid conduit has a series of finned chambers, each extending vertically between the first and second plates and horizontally between the third and fourth lateral sides of the heat exchanger.

9. 9. The microcartridge heat exchanger of claim 1, wherein the first and second working fluid flow paths are perpendicular to each other and define a cross-flow configuration.

10. 10. A microcartridge heat exchanger according to any one of claims 1 to 9, having a unitary and seamless construction.

11. A microcartridge heat exchanger according to any one of claims 1 to 10; a housing having an opening into which the microcartridge heat exchanger is mounted, the housing further comprising a first working fluid inlet duct in fluid communication with the inlet for the first working fluid, a first working fluid outlet duct in fluid communication with the outlet for the first working fluid, a second working fluid inlet duct in fluid communication with the second working fluid conduit, and a second working fluid outlet duct in fluid communication with the second working fluid conduit; A heat transfer assembly comprising:

12. a first working fluid manifold interposed between and in fluid communication with the first working fluid inlet duct and the first working fluid inlet; a second working fluid manifold interposed between and in communication with the second working fluid inlet duct and the second working fluid conduit; The heat transfer assembly of claim 11 further comprising:

13. 13. A heat transfer assembly according to claim 11 or 12 when dependent on claim 3, wherein each of the first and second lateral sides of the heat exchanger is directly adjacent a lateral wall of the opening in the housing.

14. 1. A microcartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, comprising: a first plate defining an upper side of the heat exchanger and including an inlet for a first working fluid; a second plate defining a lower side of the heat exchanger and including an outlet for the first working fluid; a plurality of flat tubes, each extending vertically between the first and second plates, the plurality of flat tubes defining a first working fluid flow path through which a first working fluid flows in use; a plurality of finned chambers, each extending vertically between the first and second plates and horizontally between the front and rear sides of the heat exchanger, the plurality of finned chambers defining second working fluid flow paths through which a second working fluid flows in use; and the flat tubes and finned chambers are arranged in alternating layers, the arrangement extending to substantially the outermost edges of the first and second plates, respectively, and the first and second opposing lateral sides of such a heat exchanger are defined by walls of the flat tubes or walls of the finned chambers, respectively; the microcartridge heat exchanger is configured to be contained in a housing, the housing comprising a first working fluid inlet duct, a first working fluid outlet duct, a second working fluid inlet duct and a second working fluid outlet duct, the configuration being such that when the microcartridge heat exchanger is in the housing, the first working fluid inlet duct is in fluid communication with the inlet for the first working fluid, the first working fluid outlet duct is in fluid communication with the outlet for the first working fluid, and the second working fluid inlet and outlet ducts are in fluid communication with the finned chamber; Microcartridge heat exchanger.

15. 15. The microcartridge heat exchanger of claim 14, further comprising turbulators disposed within each flat tube.

16. 16. The microcartridge heat exchanger of claim 15, wherein the turbulators include a plurality of pin-like structures, each pin-like structure extending across the width of the flat tube.

17. 17. The microcartridge heat exchanger of any one of claims 14 to 16, wherein the finned chamber comprises a plurality of chevron-shaped fins, each chevron-shaped fin being pierced by a plurality of openings.

18. A microcartridge heat exchanger according to any one of claims 14 to 17; a housing having an opening into which the microcartridge heat exchanger is mounted, the housing further comprising a first working fluid inlet duct in fluid communication with the inlet for the first working fluid, a first working fluid outlet duct in fluid communication with the outlet for the first working fluid, a second working fluid inlet duct in fluid communication with the finned chamber, and a second working fluid outlet duct in fluid communication with the finned chamber; A heat transfer assembly comprising:

19. 20. The heat transfer assembly of claim 18, wherein each of the first and second lateral sides of the heat exchanger is directly adjacent a lateral wall of the opening in the housing.

20. 1. A microcartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, comprising: a first plate defining an inlet for a first working fluid; a second plate defining an outlet for the first working fluid; a plurality of conduits ("first working fluid conduits") disposed across the first and second plates and defining a first working fluid flow path through which a first working fluid flows in use; a plurality of conduits ("second working fluid conduits") disposed across the first and second plates and defining second working fluid flow paths through which a second working fluid flows in use; and the first and second working fluid conduits are arranged in alternating layers; the plate and the working fluid conduit are integrally formed with one another; The microcartridge heat exchanger is configured to be contained in a housing, the housing having a first working fluid inlet duct, a first working fluid outlet duct, a second working fluid inlet duct and a second working fluid outlet duct, such that when the microcartridge heat exchanger is in the housing, the first working fluid inlet duct is in fluid communication with the inlet for the first working fluid, the first working fluid outlet duct is in fluid communication with the outlet for the first working fluid, and the second working fluid inlet and outlet ducts are in fluid communication with the second working fluid conduit. Microcartridge heat exchanger.

21. 21. The microcartridge heat exchanger of any one of claims 1-10, 14-17 and 20 formed via an additive manufacturing process.

22. 1. A cartridge heat exchanger for transferring heat between a first working fluid and a second working fluid, the cartridge heat exchanger comprising: a cartridge body; The cartridge body is first working fluid inlet and outlet ports disposed at opposite ends; second working fluid inlet and outlet ports disposed on opposite sides; an interior wall structure defining a plurality of first working fluid conduits ("first conduits") extending from one end of the cartridge body to the other between first working fluid inlet and outlet ports, the first conduits having an elongated cross-sectional dimension, the first conduits being spaced apart from one another, the spaces between adjacent first conduit walls defining second working fluid conduits ("second conduits") extending from one side of the cartridge body to the other between second working fluid inlet and outlet ports; a sealing surface disposed about the cartridge body and separating the first actuating fluid inlet and outlet ports from the second actuating fluid inlet and outlet ports; and The cartridge heat exchanger is configured to be contained within a housing, the housing having a first working fluid inlet duct, a first working fluid outlet duct, a second working fluid inlet duct and a second working fluid outlet duct, the configuration being such that when the cartridge heat exchanger is within the housing, the cartridge body is sealed to the housing at respective sealing surfaces, and the first working fluid inlet duct and outlet duct are in fluid communication with the first working fluid inlet port and outlet port, and the second working fluid inlet duct and outlet duct are in fluid communication with the second working fluid inlet port and outlet port. Cartridge heat exchanger.

23. 23. The cartridge heat exchanger of claim 22, wherein the first conduit comprises a flat tube.

24. 23. The cartridge heat exchanger of claim 22, wherein the first conduit comprises a curved pipe.

25. 25. A cartridge heat exchanger according to any one of claims 22 to 24, wherein the space between adjacent first conduit walls (i.e. the width of the second conduit) is substantially constant.

26. 26. A cartridge heat exchanger as claimed in any one of claims 22 to 25, wherein each of the first conduits has turbulators extending between their walls to promote turbulent flow of the first working fluid in use.

27. 27. A cartridge heat exchanger according to any one of claims 22 to 26, wherein each of the second conduits has a finned chamber in which an array of fins extends between adjacent walls.

28. 28. The cartridge heat exchanger of claim 27, wherein the array of fins comprises rows of chevron-shaped fins with through holes aligned in the direction of flow of the second working fluid.

29. 29. A cartridge heat exchanger according to claim 28, wherein adjacent rows of fins are offset from one another to promote turbulent flow of the second working fluid, in use.

30. 30. A cartridge heat exchanger according to any one of claims 22 to 29, wherein the sealing surfaces comprise flanges around the first working fluid inlet and outlet ports which, in use, provide a seal with the housing.

31. 31. A cartridge heat exchanger according to any one of claims 22 to 30, formed by an additive manufacturing process.

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